Grinding machine



April 9, 1935. M. ROMAINE 1,997,551

GRINDING MACHINE l I Filed Dec. 5, 1952 9 Sheets-Sheet l @Wn/wang April 9, 1935.

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M. ROMAINE 1,997,551

@BINDING MACHINE Filed Dec. 5,11952 9 Sheets-Shet 2 April 9, 1935. M. ROMAINE GRINDING MACHINE 9 Sheets-Shea*l 3 Filed Deo. 5, 1932 l) bmw W M Twmw Y f /V 7 w N X W M f f R \C\. N. NNN, w Y m Q @Hvwvowwwwww l April 9, 1935.v M. ROMAINE 1,997,551

GRIND;NG MACHINE Filed Deof, 1952 9 sheets-sheet `4 1459/5 ffl/0 f4.1 M J4;

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GRINDING MACHINE -Fi'led Dea. 5, 1952 9 sheets-sheet e KWNXNN 5mm/MAJ 'April' 9, 1935. M, ROMMNE 1,997,551"

GRINDINGr'MACHINEv y Filed Dec. 5, 1952 9 sheets-snaaiy Y Iig f5 ///////////////l////////////////////1///// 3mm/M if@ Y? /V//Ma/w/M April 9, 1935.

` M. ROMAINE -GRINDINQMACHINE` 9 Sheets-Sheet 8 Filed Dec. 5, 1932 April 9, 1935- M. @MAINE 1,997,551

GRIYNDING MACHINE Filed Dec. 5, 19:52 9 sheets-shed 9 @2M www Patented Apr. `9, 1935 UNITED STATES Gamnmq momma Millard Romaine, Cincinnati, Ohio, assignorto Cincinnati Grinders Incorporated, Cincinnati, Ohio, a'corporation of OhioA Application December 5, 1932, SerlalNo. 645,724

5 an improved automatic grinding machine of the center type for expeditiously and accurately producing cylindricaljwork pieces.

l Another object ofthe invention is the'provision of improved hydraulic and electrical control l means for automatically operating and controlling machine tools, especially grinding machines.

A further object of the invention is the provision of improved means for effecting and controlling the relative feed of a tool and a work .piece whereby to automatically `control the size of said work piece while expeditiously producing same.

A still further object ofthe invention is the provision of improved hydraulic means for effecting said relative feed between the tool and work.

It is also an object of this invention to provide l improved means for automatically adjusting the relative positions of the parts to automatically take care of reduction in size of the tool, such as a grinding wheel, due to wear thereon and ,the trimming or truing away thereof.

It is a still further object of the present invention to provide improved interlocked means between the trimming or truing devices and. the normal feeding mechanism so that the relative position of the work and tool is automatically compensated for due to the truing of the wheel and to thereby maintain the proper desired relative relation between the work and tool in order to expeditiously produce successive work pieces at a minimum expense and within prescribed size limits.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings,' forming a part thereof, and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the ,scope of the appended claims,vwith out departing from or exceeding the spirit of the invention.

In the drawings:

Figure 1 is a front elevation of a grinding machine embodying the improvements of this invention.

l Figure 2 is a top plan view of the machine shown in Figure 1 f t seen from the right hand side of Figures 1 and 2.

VFigure 4 is a transverse fragmentary sectional view through the feeding mechanism as seen, for example, on line-4 of Figure 2 Figure 5 is a view as seen from 4line 5--5 on 5 Figure 4, illustrating the parts partly in elevation and partly in section.

Figure 6 is a longitudinal sectional view through the tail stock as seen from line 6-6 on Figure 2.

Figure '7 is a longitudinal sectional viewthrough the head stock as seen from line 1-1 on Figure 2.

Figure 8 'is a longitudinal sectional .view through the truing tooLactuating mechanism, as seen from line 8-8 on Figure 2. Y

a Figure 9 is a vertical sectional view through the work loading and ejecting mechanism taken, for example, on line 9 -9 of Figure 2.

` Figure 10 is a transverse sectional view through the truing timing mechanism, as seen from line Ill-I0 on Figure 4, and forming" a detail of the invention.

Figure 111 is a sectional view taken on line H`II of Figure 10.A p

Figure 12 is a sectional view taken on line I2-I2 of Figure 10.

Figure 13 is a view partly in section and partly in elevation of the ycontrol box housing the various valves and adapted to be mounted on the forward face of the bed.

4Figure 14 is a sectional view through a stop valve forming a'detail of the circuit control aS seen from line |4-I4 on Figure 17.

Figure 15 is a diagrammatic view illustrating the hydraulic and electrical circuitsutilized in the performance of the invention.

Figure 16 is a vertical sectional view through the axis of pivotance of the tool carriage taken on line lli- I6 of Figure 3.

Figure 17 is a' sectional view taken on line `I1|1 of Figure 5.

Figure 18 is a sectional view taken on line I8--I8 of Figure 5.

Throughout the several views of the drawings l15- similar reference 'characters are employed to denote the same or similar parts.

Grinding machines are divided into a plurality of types and classes `depending upon the way the work is presented to the wheel or tool or on the type of Work produced thereby. Among these classes of'grinding machines are what is known as center type machines, in which the work isl supported between opposed or terminal supports` 0r centers during the grinding operation thereon. 55I

These machines are in turn divided into two classes, one in whichl the work is traversed longitudinally past the operative face of lthe grinding wheel during the grinding thereof and the other in which the work is held stationary as respects axial movement and the grinding wheel fed into the work. In thelatter type of grinding, commonly known as plunge cut grinding, the wheel is generally given a slight axial movement for breaking up grinding lines on the work and evenly distributing the Wear across the face of the wheel.

The present invention has particular reference to the plunge cutting class of grinding kmachines and, as set forth in the objects, it is the purpose thereof to produce an improved automatically operated center type plunge cut grinding machine. It is to be understood, however,

that the controls and unique mechanism disdrawings and to be subsequently dened have, with very slight modification, equal application to the operation and control of other types offgrinding machines and machine tools generally. y

In general the present invention contemplates the use of an oscillating type of wheel head oscillatable toward the work together with improved hydraulically operated means for effecting the said oscillation of the head. There is also utilized anddisclosed an improved work loading and ejecting mechanism for automatically bringing the work into position for engagement by the work centers and automatically engaging the centers with the work. A sizing mechanism is employed for controlling the size of the work and for stopping further reduction thereof when closed in the the work reaches the said desired or final size.

33 to the upper surface of All of these various and several movements are interlocked in such fashion as to insure the sequential operation thereof. I

Specifically, the machine comprises a. bed or base 25 having formed in its upper surface V and fiat guideways 26 and 21 receiving correspondingly shaped guide ribs depending from the under surface of a work supporting table 28. The Work table 28 is in turn formed on its upper surface with a dove-tailed guiding tongue 29 received in a groove formed in the under surface of the opposed head and tail stocks 39 and 3l. In order to adjust the position of the work table 28 relative to the bed 25, there is provided usual mechanism, such as a rack and pinion, not shown, operated byla transverse shaft 4H carried by the bed 25 to which is secured a hand wheel 4| 2 for rotating same. The bed 25 has projecting rearwardly therefrom an extension 32 which supports the grinding wheel and feeding mechanism, which will be described in detail later.

The head stock 30, see Figure 7, is of `the selfcontained type and comprises a casting or casing which is secured a prime mover or 'motor 34 having keyed or otherwise secured to its shaft 35 a gear 36. rllhe gear 36 is enclosed within a supplemental housing 31 in which is also journaled the shaft 35 driven by the motor. Meshing with the gearA 36 is a gear 38 on one end of a shaft 39 rotatably journaled in supplemental housing 31. The other end of the shaft 39 has keyed or otherwise secured to it a pinion 40 meshing with a carrier 4I on a final driven shaftm42 journaled partially in the housing 31 and partially in the head stock casting 33. The driven shaft 42 terminates in a pinion 43 which meshes with a gear 44 of the work chuck or driver 45. The chuck or driver 45 terminates in a plurality of lugs or ears 46 between each pair of which is pivoted fingers 41. The inner surface of the fingers `41 is tapered to provide cam faces A48 co-operating with the cam face on the inner surface of a ring 49. The ring 49 is carried by the chuck-driver 45 and slidable relative thereto so that when it is retracted springs 50, which have one end secured to the outer end of the chuck jaws 41 and their other ends to a fixed part of the chuck-driver 45, may oscillate said jaws to release the work. The ring 49 is adapted to be axially shifted by hydraulic pressure and is directly engaged by a flange 5l formed on the end of a sleeve or shaft 52 slidable through bearings provided by a sleeve 53 secured in the head stock casting or casing 33. The rear end of the shaft 52 is provided with a reduced portion 54 to which is secured in any desirable manner a piston 55 operable in opposite directions through a cylinder 56 carried by the rear end of the head stock casing 33 and in axial alignment with the shaft 52. The piston 55 is provided on opposite ends'with reduced portions 51 and 58 adapted to respectively enter counterbores 59 and 60 formed in opposite ends of the cylinderE and co-operating with one another to form dash pots for cushioning the limits of movement of the piston 55. The inner end of the shaft 52 is provided with a counterbore 6| into which is pressed a sleeve 62 provided with a socket 63 and an aligned reduced bore 64. Received in the socket 63 is the head stock center 65 from which projects a stem 66 passing through the reduced bore 64. Surrounding the stem 55 and abutting on opposite ends with the seat of the socket 63 and the center 65 is a spring normally tending to urge the center to the right, as'seen in Figure 7, this movement of the center being limited by a lock nut 61 on the end of the stem 66 engaging with the outer surface of the sleeve 62. 'vided with a. keyway 68 receiving a suitable key 69 carried by the casing 33 which prevents relative rotative movement of the shaft 52. Adjacent the keyway 68 the shaft 52 is provided circumferential groove 10 receiving the nose 1I of .a lever 12 pivoted intermediate' its ends to a fixed part of the head stock casting 33. The lever 12 has pivoted to its lower end one end of a plunger 13, the outer end of which is connected with the movable part of a double throw electrical switch 14 whereby the said switch is closed at. each end of movement of the shaft 52. The cylinder 56 is provided at opposite ends with ports 15 and 16 with which connects one terminus of a pair of hydraulic conduits as will later appear.

The tail stock 3|, see Figure 6, comprises a against movement a sleeve member 18 providing at lopposite ends thereof bearings for an axially shiftable spindle 19. The spindle 19 is provided intermediate its ends with a key way 89 receiving the key 8l carried by the fixed sleeve 18 which prohibitsany relative rotative movement of the spindle 19.' At one end, the spindle 19 is provided with a tapered socket 82 receiving therein the tapered shank of tail stock center 83. The other endl of said spindle is provided with a counterbore 84 in which is disposed a compression spring 85 abutting on one end with the seat of the counterbore and on the other endwith the inner. surface of a head 85 carried by a piston rod 81. Secured to the outer end of the piston rod 81 is a piston with aA 88 reciprocable through a cylinder 89 secui ed to 75 spindle 19. The piston 88 is provided on opposite ends with bosses similar tothose above described in connection with the head stock piston which co-operate with recesses formed at the end of the cylinder and form dash pots to cushion the limits of movement of the piston and parts actuated thereby. To insure retraction of the -spindle 'I9 upon corresponding movement of the piston 88, the said spindle has secured to its end a collar 90 co-operating with the shoulderk formed by the piston rod head 86 whereby movement of the piston rod to the right, as seen in Figure 6, carries with it the said spindle 19 and center 83. The spindle 19 is also provided intermediate its ends with a circumferential groove 9| to provide shoulders for engagement with the upper end or nose 92 of a lever 93 pivoted intermediate its ends as at 94 to the casting 11. The other Vencl of the lever 93 has pivoted thereto a plunger 95 in turn having its free end connected to the movable member of aidouble throw electrical switch 95. The cylinder 89 is provided in opposite ends with ports 91 and 98 with whichdconnect the termini of suitable hydraulic conduits for conveying an hydraulic medium thereto under pressure, as will be later described.

The work piece 99 is automatically brought to and aligned with the centers at which time the centers are actuated toward one another to pick up said wo'rk and upon the completion of the work it is automatically removed from between the centers. The mechanism for accomplishing .y this operation is best illustrated'in Figures 2 and 9. As there shown, the bed extension 32 has bolted or otherwise secured to it -an upstanding bracket which projects upwardly above the grinding wheel. The bracket |00 has projecting outwardly from it into overlying relation with the grinding wheel, a pair of supporting bars |0| and |02, shown here as channel irons, although they may be of any desiredor convenient configuration. Secured to the channel irons-40| and |02 is a cylinder |03 held by the brackets |04 against any inadvertent movement. The cylinder |03 is closed at its opposite ends by heads and |06, the latter being in addition provided with a stuffing box |01 through which passes a piston rod |08. Secured to the inner end of the piston rod y |08 is a piston |09 adapted to be actuated through the cylinder |03 by means of an hydraulic medium or fluid under pressure and introduced into the cylinder through the ports IIO and III respectively provided at the lower and upper ends thereof. The upper endf therpiston rod |03 is connected in any suitable or desirable manner to an arm I I2 projecting from a carrier or slide I I3. The slide I|3 has secured to its lower end, on opposite sides thereof, as by means of cap screws or the like l I4, carrying arms I I5 spaced so as to straddle the grinding wheel. The lower ends of the arms ||5 are formed to providel a cradle IIB in which the Work is carried during its movement into and out of grinding position.

The lower supporting arm or channel iron |02 of the bracket |00 carries a magazine I I1 for unfinished work pieces which are discharged by gravity into the cradle I I6. To prevent inadvertent discharge of the work pieces from the magazine I I1, there'isprqvided a shutter I I8 vertically shiftable relative to the standards or guides IIS associated with the magazine. The shutter IIS has projecting from its face adjacent the carriage II3 a lug |20 adapted to be engaged by a ledge I2 extending outwardly fron the arms I I5 and in such a position as to engage and raise the shutter .|I8. Beneath the magazine ||1 and supported by the arm |02 is a finished work receiving 'chute or platform`|22 to which the work pieces are shunted during the upward movement of the carrier I I3. For effecting the automatic shunting' of the work, each of the arms -I I5 has pivoted to its lower end ngers |23 held by gravity in the position shown in Figure 9. The fingers I 23 have projecting from their rear end, and yin a plane above the plane of their pivots |24, a lug |25 adapted during the upward movement of the carrier II3 to be engaged by a ledge |25 secured to the outer surface of the cylinder |03. From a study of Figure 9, it will be seenthat as the carrier II3 is travelling upwardly with a finished work piece disposed in the cradle IIS and as soon as the work comes even with the discharge chute or platform |22 the discharge fingers lugs |25 will engage the ledge |26 thereby oscillating said fingers in a clockwise direction and ejecting the work from the cradle onto the platform of chute |22. Continued upward movement of the carrier then causes the lug |2I, of the arms H5, to engage the shutter lug |20 and elevate the said shutter thereby releasing the lowermost work piece in the magazine I I1. At this time the cradle is at the end ofthe magazine in position to receive the work piece therefrom.

The bed extension 32 has mounted thereon a bed plate |21 which in effect constitutes a tank or sump for an hydraulic medium, preferablyoil, utilized in the operation of the several units of the machine tool organization. Movable on the upper surface of the bed. plate I 21 is theslide |28. As seen in Figures 4 and 16, the forward en'd of the slide |28 has an upstanding rib-like portion |29 the lateral edges of which are faced off and provided with aligned bores |30 and I3I respectively receiving trunnions or pivots |32 and |33.

|34 to prevent any relative movement of the trunnions with respect to their bearings. The trunnions extend beyond the lateral faces of the rib portion |29 and are respectively received in suitable bores formed in arms |35 and |36 depending from the carriage |31. The carriage |31 has The trunnions are held in place by lock screws journaled in its forward end a spindle |38 to one end of which is secured a grinding wheel |39, the -wheel being suitably enclosed within aguard |40 secured in any desirable manner to the carriage |31. Beyond the spindle the carriage |31 has a at surface |4| to which is secured inany desirable manner, preferably adjustably, a prime mover or motor |42. The motor shaft |43 of the motor |42 has keyed or otherwise secured to it a sheave |44 having a plurality of grooves formed therein each adapted to receive a flexible belt ,|45 of V-shape in cross section. The belts |45 are in turn trained about a sheave or pulley |46 keyed or otherwise secured to the outer end of the grinding wheel spindle |38.

t From the foregoing it will be noted` that the grinding wheel carriage |31 is mounted for oscillation relative to its supporting slide |28. The carriage |31 is adapted to be oscillated toward the Work to effect a stock removal therefrom and to thereby reduce the said work to the desired size and contour, and is adapted to be fully retracted to permit replacement of the work. f

For effecting the oscillation of the carriage |31 the slide rib |29 is provided with a cylinder |41 receiving in the bore thereof a pistonv |48. rIfhe cylinder is closed at opposite ends by means of.

heads (|49 and |50, the latter carrying a stuffing box |5| through which passes a piston rod 52 having its inner end secured to the piston |48. The other end of the piston rod |52 is secured to a plate or carrier |53 which carries a cam for effecting the oscillation of the carriage 31. As shown in Figures 4 and 5, the plate |153 carries the cam |54 having an inclined operative .surface |55 incliningI upwardly to the left, as seen in Figure 4. 'I'he upper or inclined surface |55 of the cam |54 is contacted by a roller |56 secured to a shaft |51 freely rotatably journaledin suitable bearings provided by arms |58 and |59 depending from the lower surface of the carriage |31. To reduce friction and maintain proper alignment 'of the plate |53 and cam |54, the under surface |60 of the cam |54, see Figure 5, rests on an anti-friction roller |6| carried by a shaft |62 rotatably journaled in arms |63 and |64 projecting upwardly from the upper surface of the slide |28. The piston |48 and piston rod |52 and parts connected therewith are adapted to be actuated by thehydraulic medium under pressure which enters the cylinder at opposite ends through suitable ports |65 and |66, which will be described in detail later.

In order to circulate the hydraulic medium, the slide |28 isprovided with a lateral extension |61, see Figure 5, forming a base for the support of a suitable pump I 68 which may be of any suitable or desirable rotary type. The pump |68 has its driven shaft |69 disposed co-axial with the axis of the trunnions |32 and |33 and secured to the rotary shaft |69 is a suitable sheave or pulley |10. Trained about the sheave or pulley |1tD is a flexible belt |1| which in turn extends about the sheave or pulley |46 on the end of the spindle |38. From this it will be seen that the pump |68 is constantly driven during the oscillation of the carriage |31 since the oscillation takes place about the axis of the shaft |69 thereby at no 'time varying the separation between the axesof said shaft and the spindle.

As shown diagrammatically in Figure 15, and structurally in Figure 3, the pump |68 has extending from its suction side a pipe or conduit |12 having its other terminus in the tank or sunp |21. Extending from the other side of the pump |68 is a discharge conduit |13 through which the medium passes under pressure. The pipe or conduit 13 terminates at a start and stop valve, shown diagrammatically in Figure 15 and structurally in Figure 13. As shown in the latter gure, the start and stop valve, indicated generally by the numeral 14, comprises a valve bushing |15 provided with an intake and an exhaust port |16 and |11 respectively. It is with the intake port that the pipe or conduit |13 connects. Enclosed within the bushing |15 is a spool type valve |18 having formed centrally thereof'y a cannelure |19 for connecting the: intake and exhaust ports when the valve is in one position or in alignment with said ports, and for cutting off flow through the bushing |15 when out of registry therewith. The valve |18 has extending from its one end a valve stem |80 connected by a pin and slot connection 8| with a starting and stopping lever |82. The lever |82 has its lower end pivoted at |83 to lugs or ears |84 projecting from the side of a plate or housing memba |85 secured to the forward face of thel bed 25 within convenient reach of the operator. The plate or housing |85 has secured therein the starting and stopping valve bushing |15 and in addition supports several other valves for effecting and controlling the various operations of the machine, as will belater made clear.

Connected or in alignment with the discharge port |11 of the starting and stopping valve |14 is the terminus of a conduit or port |86. The other terminus of thishconduit or port |86 is connected with branch conduits or ports |81 and |88, the former terminating at a pilot valve, while the latter connects with the head and tail stock centers control valve. The pilotvalve is shown structurally in Figure 4 and diagrammatlcally in Figure 15. This valve comprises a stern portion |89 and spools |90 and nelure |92 between stem |89 and 'spool |90 and cannelure |93 between the spools |90 and |9|. The stem portion |89 is provided with rack teeth |94 meshing with the teeth on rack pinion |95 which is journaled for rotation in a suitable block or casting |96, see Figure 4, secured to and car- -ried by the slide |28'.A Beyond the block or casting |96 the pinion |95 has projecting from it a lever |91 adapted to be disposed in the path of movement of reversing dogs |98 and |99 adjustably secured in a T-bolt slot 200 formed in the plate |53. The pilot valve when in one position is adapted to connect the branch pressure conduit |81 through the cannelure I 92 with a conduit or port 20| which terminates at one en'd of a reversing valve chamber 202. The reversing valve lchamber 202, see Figure 4, is formed in the 'block or casting |96 and encloses a spool type piston valve 203. In a second position of the pilot Valve it is adapted lto connect by Way of the cannelure |93 the branch conduit |81'with a conduit or port 204 terminating at the other. end of the reversing valve chamber 202. The reversing valve 203 controls the direction of movement of the feed piston |48.

The reversing valve comprises spool portions between which is formed cannelures 204a and 205. Connected with the chamber. 202 is one end of a conduit 206 which may be a branch pressure conduit similar to conduits or ports |81 and |88 or may be a continuation of the main pressure conduit |86'. This conduit is adapted to be connected alternatively and respectively through the cannelures 204a and 205 With conduits 201 and 208, the former terminating in the port |65 formed in one head of the main cylinder |41 and the latter with the port |66 formed in the main cylinder at the other end thereof. In addition, the chamber 202 has extending from it exhaust ports or conduits 209 and 2 I0 adapted respectively to be connected with the conduits 201 and 208 when said conduits are not connected with the main or branch pressure conduit 206. The said conduits 209 and 2| 0 respectively terminate at a stop valve indicated generally by the numeral 2|| and a speed control valve indicated generally by the numeral 2|2. The stop valve 2| determines the ultimate retracted position of the carriage |31 while the speed control valve effects and controls the rate of movement of the grinding wheel toward and relative to the Work while effecting a stock removal therefrom. I

.The stem |89 of the pilot valve is formed on its one end with a head 2|3 from which projects the core 2|4 of a solenoid adapted to be operated upon by the coil 2| 5. This solenoid effects the operation of the pilot valve for automatically shifting same. The pilot valve is shifted in the other direction by the ldog |99 during the normal operation of the machine. In the event, and as will later appear, the parts are Hable to become inoperatively vdisassociated from one another, the reversing dog I 98 will effect a reversal thereof or shifting thereof. 'I'he shifting |9| forming canj of the pilot valve connects' either-of the lines 20| or 204 respectively with exhaust pressure lines 233v or 234 with the exhaust return line 235 which terminates in the sump ortank |21. This permits the escape of the hydraulic medium between the ends of the reversing valve 203 and the adjacent ends of the valve chamber 202 so that the pressure introduced in the other end of said the coil spring 220, disposed within the chamber 2|6, and contacting on its other end with the base of said chamber.' The spring 220 tends to. shift the valve 2|9 in a direction to close ofi or prevent a flow of uid from the conduit 210 through the chamber 2|6 into the conduit 2|1. The amount of movement permitted the valve 2 I9 by the spring 220 is controlled by a valve actuatonwhich abuts with the end of the valve opposite to that contacted by the spring and shown in Figure 4 in the nature of a vertically shiftable plunger 22|. The. plunger 22| is provided on lts upper end with a clevice 222, see Figure 17, between the arms of which is disposed a lever 223. The lever 223 is therefore pivoted intermediate its ends to the plunger 22| and has its one end pivoted at 224 to a bracket or lug 225 extending upwardly from the casing or casting |96. 1 The other or free end of the lever 223 rotatably carries a roller 226 contacting. with a cam face 221 formed on cam plate 226 secured to and carried by the plate or carrier |53. o

From this it Awill be seen that as the carrier |53 is mcvedby the'piston |48 for eiecting an infeed of :the grinding wheel through the cam surface |55, the cam surface 221 is moving therewith and controls the position of the valve ||9 for thereby controlling the exhaust through` the lines 2|0 and 2|1 for controlling the rate of feed of the grinding wheel into the work. As will be noted from Figure .4, this cam is of a gradual taper extending from the point 229 at the left hand endA of the cam 228, as seen in these iigures, to the point 230 from which a short steep incline 23| extends to the l,horizontal portion 232.' When the grinding wheel is completely retracted 'the cam face 2.32- is rin engagementwith the roller' 226 forA completely depressing the valve 2|9 and thereby completely opening the said valve whereupon a movement of the piston in a'feed direction, namely right as seen in Figure 4, will atfirst be effected at a rapid rate until the cam portion 23| comes into play 'whereupon the valve will be comparatively rapidly allowed to go to a near closed position for thereby throttling the flow of the uid and reducing the rate of feed of the Vgrinding wheel. As the-cut nears its conclusion,

and since it is desired to have a high finish on the work, the rate of feed is still further reduced, thereby insuring the proper surface on the Work.

The retracting movement of the carriage |31 is stopped, as noted above, by the stop valve 2| This valve during the retraction of the carriage |31 normally connects the exhaust conduit 209 with 'the branchexhaust return line 236 which in turn connects with the main return exhaust line 2|8. 'I'he `.valve 2|| is shown diagrammatically in Figure 15 and structurally in Figures 14 and 1'! and comprises a bushing 231. Thev bushing 231 is carried by the block or casting |96 and encloses a spool type of valve for providing cannelures 233 and 239. The valve has extending from each end thereof a stem 240 and 24| each stem passing through a stufling box 242 .provided at the ends of the valve bushing 231. The stem 24| is provided at its terminus with an adjustableabutment 243 here conveniently shown as a bolt or screw threaded into the end of the stem 24| and locked into adjusted position by the lock nut 244. Carried by the plate member |53 is a dog or arm 245 adapted when the plate has reached a position for effecting the complete retraction of the grindingwheel to engage with the abutment 243 and thereby shift the cannelure 238 out of registry with the conduits or ports 209 and 236 thereby cutting voff any further exhaust ow through said conduits and stopping further movement of the main feed piston |48. The shifting of the valve through the arm 245 is against the yielding resistance of a spring 246 that surrounds the valve stem 240 and abuts on opposite ends with the valve and the stuffing box 242. The valve stem 240 is pivotally connected at 241 with the movable core 248 of a solenoid 249 which during a certain portion of the cycle of the machine further shifts the valve jagainst the resistance of spring 246 thereby again connecting the exhaust conduits 209 and 236 with one another, this time,

i however, connecting same through the cannelure 239 instead of the cannelure 236.

As was noted above, the infeed of the grinding Wheel is automatically reversed by the shifting of the pilot valve by electrical means including the ,solenoid 2|4-2|5. This mechanism is controlled by a sizing device which completes an electrical circuit and is shown diagrammatically in Figure 15 by the switch 250 and structurally .in Figure 9. l.As shown in the latter figure, the sizing mechanism comprises a bracket member having the base ange 252 which rests on the upper surface of the work table 26 being secured thereto byv means of bolts 253 passing through suitable elongated perforations in the ange 252 whereby lateral adjustment of the bracket may' take place. At the upper end, the'bracket 25| is formed with a chamber 254 in which is disposed a Crack plunger 255 having rack teeth 256 thereon meshing with the teeth of a gear 251 keyed or otherwise secured to a shaft 258 rotatably journaled in the side walls of a cover plate 259 secured to the bracket 25| .and completing the chamber.,

254. 'I'he gear 251 also meshes with the teeth of a pinion 260 likewise keyed or otherwise secured to a shaft 26| journaled in the walls'of the cover plate 259. One end of the shaft 26|.extends beyond one of its bearings and has secured to said extending portion a sizing ringer 262. A spring .263 is also enclosed within the chamber 254 and abuts on one end with the plunger 255 and ontheother end with the plug 264 forming thev rear closure for the chamber 254. The spring tends to finger snaps past center, thereby permitting. the spring to shift the plunger to its right hand limit of movement. A The said right hand end of the plunger 255 carries a switch contact 265 to which is secured one end of an electrical wire or conduit 266, and this contact 265 engages with a contact 261 carried by the plug 268 closing the other end ofthe chamber 254. vThe contacts 265 and 261 constitute the switch member 250 in the hydraulic electrical diagram illustrated in .Figure 15.

In order to reset the sizing device for anew work piece, there is provided a bell crank lever 269 having an arm 210 underlying the work carrying slide ||3 and disposed inthe path of -irnovement of an abutment 21| projecting from a lug 212 integral with the cradle H6. The other arm 213 of the bell crank 269 flanks the side of the bracket 25| and engages with a lug 214 projecting outwardly from the plunger 255 through the wall of the chamber 254. .A spring 215 has one end anchored at 216 to the bracket 25| and the other end connected at 211 with the arm 213. As the work carrying slide travels upwardly with a ilnished sized work piece the spring 215 contracts and oscillates the bell crank 269 about its pivot and through its arm 213 in engagement with the plunger lug 214 retracts the said plunger against' the yielding resistance of the spring 263. This disposes the sizing nger 262 in an upwardlly inclined direction as respects the work having reference'to the disclosure in Figure 9. This then permits the unfinished work that is being carried by the carriage ||3 to be lowered into operative position without interference by the said finger 262. As the carriagev descends, however, the lug 21| thereon engages with the arm 210 and oscillates the bell crank 269 in a clockwise direction against the yielding resistance of its spring 215.

This movement of the bell crank, however, do'es not take place until after the work is below the sizing finger and as the said bell crank is oscillated in a clockwise direction, the arm 213 is removed from the plunger lug 214 so that the plunger spring 263 can again operate as above described for bringing the sizing nger into lcontact with the surface of the now unfinished work piece.

'The other end of` the wire 266 which extends from the switch contact 265 may connect with one of the wires or leads 218 or 219 of the main electrical supply. The 'other contact 261 of this switch has extending from it an electrical conduit or wire 280 which, as shown in Figure 15, terminates at a time Vrelay 28|. `Extending from the conduit or wire 280 is a wire 282 which has its other terminus connected to one end of the solenoid coil 2|5. The other end of the solenoid coil is connected by a wire 283 with the other lead 218 or 219 of the main current supply. From this it will be seen lthat as soon'as the work piece is reduced tov the desired size, the solenoid 2y|42|5 is energized for shifting the -pilot valve and thereby connecting the hydraulic pressure in branch pressure line |81 with the proper end of the reversing valve chamber 202 for shifting said valve and reversing the connections to the mainpiston cylinder |41.`-A s shown in Figure 15, the shifting of the pilot valve'by the solenoid 2 |4--2 5 will be to the'left and'will connect the pressure'i-n the conduit |81 throughthe cannelure |93 with the j right hand end of the reversing valve chamber '-n'ects theconduit 288 through the cannelure 295 with the branch pressure line 206 for actuating the piston |48 within the cylinder |41 to the left.

The time relay 28| connects the electrical conduit 280 with the coil of a solenoid 284 adapted for shifting the valve which controls the hydraulic connection with the head and tail stock centers pistons. The time relay 28| momentarily interrupts the ow of the current therethrough until -after the solenoid 2|4-2I5 has been energized 'for shifting the pilot valve ,and initiating a re- .closes a spool type valve for providing cannelures 281 and 288. The valve has projecting from it a stem 289 to which is secured a pairof collars 290 receiving between them the ball end of a valve shifter 29| pivoted at 292 to a ilxed part of the plate or housing 85. The other end of the shifter 29| has pivoted to it a pair of solenoid cores, one of which is the solenoid 284 above described, and the other being indicated by the reference character 293. 'Ihe cannelures 281 and 288 are adapted to alternately connect the branch pressure conduit |88 with the conduits 294 and 295 connecting the remaining conduit with branch return conduits 296 and 291 in turn'connected with the main return conduit 2|8. The conduit 294 is simultaneously connected with the port 15 of the head stock cylinder 56 and the port 98 of the tail stock supporting cylinder 89 while the conduit 295 is simultaneously connected with the port 16 of the head stock cylinder 56 and the port 91 of the tail stock cylinder 89. From this it will be seen that the two centers are simultaneously either actuated toward one another to pick up the work or simultaneously actuated from one another to release the work. It will further be noted that as soon as the work piece has been completed and the grinding wheel retracted therefrom the said centers are actuated away from one another to release the work piece so that it may be removed from the machine.

Each of the head and tail stocks, as was noted above, has respectively associated with it a double switch 14 and V96 shown diagrammatically in Figure 15 by the switches 298, 299, 300 and 30|. The switches 298 and 30| are electrically connected in series by means of -the electrical conduit 362 while the switch 30| is further electrically connected by the wire 303 with the negative lead 219 of the main power source. The switch 298 is also further electrically connected by means of a wire or electrical conduit 304 with a solenoid 385. The solenoid 305 is associated with the control valve indicated generally by the numeral 306 which controls the operation of the loading and ejecting mechanism for alternately connecting the hydraulic medium under pressure with the upper and lower end of the cylinder |03.

This valve 306 is carried by the plate or housin g |85 and comprises a valve bushing 391 en-v closedwithin the bushing 301 andsurrounding the valvestem 3|0 is a spring 3|2 abutting on one end with the stuffing box 3|| and on the other end with the adjacent spool of the valve. The spring normally tends to shift the valve toward the right or in the opposite direction of the operation of said valve when operated by the solenoid 305. Terminating at the valve bushing is one end of a pressure conduit or port 3|3 which connects on its other end with the pressure conduit or port 3| 4 forming an extension of the pressure conduit |88. Also terminating at the bushing 301 are branch discharge conduits or ports 3|5'and 3|6 which connect on their other ends with the discharge conduit 3|1 in turn connecting with the main discharge conduit 2|8. The cannelures 308 hand-309 alternately connect the pressure port 3|'3 with the conduits 3|8 and 3|9 respectively terminating at the ports I I I and I I0 of the cylinder |03. At this time,the other of theo conduits 3|8 and 3 I 9 is connected with either cf the branch discharge conduits 3|5 and 3|6.

AFrom this it will be s een that as soon as the work centers are completely retracted the valve 306 is shifted for effecting the withdrawal of the work from the grinding position. The work piece is discharged from the carrier in the manner above described onto the chute |22, the work carrier continuing upwardly to the upper end of its movement and aligning with the magazine I I1.

By reference to Figure 15, it will be noted that there is diagrammatically shown a switch 320 operable by the piston |09 or some part carried,

thereby preferably the carriage I I3. This switch is closed when the piston reaches its lower position, that is when the work is in grinding posi tion so that an electrical circuit is completed I. through the solenoid 305 and switches 298 and 30| when they are closed. As ysoon as the piston reaches the upper limit of its movement, however, this switch is open for thereby breaking the circuit, effecting a de-energization of the said solenoid 305 vand permitting the spring 3|2 which-fwas previously compressed to expand and shift the valve 306 to the position to effect the downward movement of the work carrier together with the unfinishedA work piece now supported thereby.

Near the lower end of the movement ofthe work carrier and prior to the closing of Athe switch 320, the work carrier closes a momentary switch 32| which has its one contact connected by the electrical conductor or wire 322 with a wire'323 extending from the positive lead 218'. The other contact ofthe switch 32| is connected by a wire or electrical conductor 324 with a solenoid S25-on the other end of the centersgvalve 285. The energization of this valve through the solenoid 325 connects the pressure to the centers cylinders for actuating the said centers toward one another to pick up the work piece that is now in positionbetween said centers to be supported thereby.

As soon as the two centers are in proper worksupporting position, the switches 299 and 300 are closed thereby. As will be seen in Figure 15, these switches are electrically connected in series i by the conductor or wire 326 while the switch' 300 is connected by the wire 321 with the wire 303 extending from the negative lead 219. The switch 299 is in turn connected by the electrical lead 328 with one end of the coil of the solenoid 249 associated with the stop valve 2||. The other end of the coil of this solenoid is connected by the wire 329 with one contact of a switch 330. The other contact of this switch 330 is connected by an electrical conduit 33| with normally closed switch 332 and by wire 323 with the positive lead 218 of the main power source. When the plate |53 is in its fully retracted position it, through a cam 333 formed thereon or carried thereby or on the' cam member |54, as shown diagrammatically in Figure 15, Icloses the switch 330 so that the electrical circuit is completed upon the closing of the switch contacts 299 and 300. As was aboveudescribed, the retraction of the plate |53, through the dog 245, secured thereto, shifts the valve 2|`| to a stop position for stopping the further retraction of the grinding wheel from the work. As seen for example in Figure 4, the plate |53 is actuated toward the left to eiect the retraction of the said wheel, therefore the dog 245 will actuate the valve 2|| likewise toward the left'or in the same direction that the valve is shifted by the solenoid 249. The movement, however, of this valve by the dog merely breaks the flow from the conduit 209 into the conduit 236 by way of the cannelure 238. 'Ihe further shifting of the valve when the solenoid 249 is energized aligns the cannelure 239 of said valve with its conduits thereby again permitting a flow from said conduit 209 into the conduit 236. At the time the movement of f the parts was stopped, the pilot valve was in itsl left hand position with the lever |91 of thepilot valve shifting mechanism extending toward the right hand dog |99, as seen in Figure 4. Thered fore, the shifting of the valve 42| I to the position to connect these parts through the cannelure 239 effects the further movement ofthe stop valve 2| in a direction to continue the rearward movement of the plate |53. This movement of the parts continues kuntil the lever |91 is engaged by the dog |99 whereupon the pilot valve is shifted lfor reversing the connections therethrough to yio tion, the centers automatically actuated toward -4 the work to pick up same, the infeed or moveme'nt of the grinding wheel toward the work automatically effected when the work is properly supported by the centers, an automatic stopping of the infeed of the wheel when thework is to the desired size, an automatic retraction of the wheel, an automatic release of the work by the centers as soon as the wheel is retracted a sufficient dis'- tance to free the work thereof, an automatic stopping of the retraction of the grinding wheel inY its inoperative position, andan vautomatic raising or `removal of the work from the grinding position to be discharged into the work'` receiving y,

trough prior to the picking up of the new unnished work piece.

In the normal operation mined by the sizing mechanism. at successive points along the cam surface |55. Sincel the grinding wheel is subject to wear and must be periodically trued to maintain a sharp accurate face, this point of size of the work along the cam face |55 will gradually progress and would eventually reach the left hand end of said face, as

seen in Figure 4. Therefore, `the parts must be reset prior to the reaching of said left hand end of the cam face.

and 335. These parts are shown diagrammati- To effect this adjustment there' `is provided on the cam platea pair of dogs 334 of the machine, the work may be brought to the desired size as deterend of the tube.

cally in Figure 15 and structurally in Figure 18 and from the latter figure it will :be noted that the shiftable slide or carriage |29 has upstanding therefrom intermediate its-ends a bracket 336.

Y'Rotatably mounted thereon as by shaft 331 is a plate 333 having proJecting from its one surface a pin or lug 339.V This pin or lug 339 lies in the path of movement of the dog 334 and 'is Aadapted to be engaged thereby for oscillating or rotating said plate when the lpiston |48 and parts actuated thereby including .the plate |53, Vreach their right hand limit of movement, as seen in Figure 4, at which time the roller |56 on the Voscillatable grinding wheel carriage |31 is near the left hand end of the cam surface |55. Secured to the plate 338 is a switch member 348 known in the trade as a mercoid switch. This type of switch comprises a glass tube sealed on opposite ends and containing mercury which when in the idle position has the mercury at one end olf the tube and when in the operative position has said mercury at the'other end of the tube for electrically bridging a pairof contacts carried by said These contacts are indicated in Figure 15 by the numerals 34| and 342, the former being connected by an electrical conductor or wire 343 with one contact of a switch 344 while the latter is connected by an electrical wire 345 with one end of a pair of solenoids 346 and 341. The other contact of the switch 344'is connected conductor or wire 348 with the wire 283.v From this it will be seen that the electrical circuit is not completed by the oscillation of the plate 338 unless the switch 344 is also closed. Since the switch 344 can only be closed when. the parts .are in the position where the carriage |31 isvvcompletely retracted vand since the switch 348 is closed when theparts are in the opposite position, thev switch closed. As will later appe'ar in detail,` this electrical interlock prevents adjustment or compensation between theparts for wheel wear Awhen the work is in actual contact with the grinding wheel and restricting said adjustment to take place only when' the parts are completely separated from one another.

The solenoid 346 is enclosed Within a suitable housing mechanism 349 secured to the 4forward face of the bed 25. The movable core of thissolenoid has pivotally connected therewith a pawl 350 adapted to engage .with a ratchet 35| keyed' or otherwise secured to la transverse shaft 352. This shaftprojectsthrough and beyond the bed plate of the bed extension 32` into a suitable bracket or housing 353 secured to the end of the bed plate |21; Integral with vor securedto the projecting end' of the shaft 352, and enclosed within the housing 353, is a pinion 354 meshing with the gearl 355 of compound idler gear 356.

4The pinion 351 of said compound gear meshes with a gear 358 integral with or secured to the rear end of an adjusting screw 359. This screw is suitably journaled in the housing 353 against any relative axial movement with respect thereto. threaded engagement with a nut 369 secured in movable slide |28`whereby the axis of pivotance of the carriage |31 is advanced as respects the axis of rotation .of the work upon the next ad' dog 335, carried Vance of the slide :|53. The

thereby, has a cam face 36| which engages with the pin or boss 339 for returning the oscillatable plate 338 to its normal position and breaking the electrical circuit through the switch 349 so that Ving from branch pressure conduit 3|4 .opposite to that in which any desirable manner to the the next retraction of the said plate upon closing of the switch `341| will not effect a furthr compensation of the Work and wheel.

As is well known, and as suggested above, it is necessaryto periodically true the operative face ofl the grinding wheel. For this reason the carriage |31, see Figure 8, has secured to it a bracket 362 to which is securedv a xed slide 363 having formed therein longitudinally thereof a guideway 364 receiving a suitable, guide tongue depending from the under surfacefof a movable carriage 365. 'Ihe carriage 365 is adapted to be translated longitudinally of the slide 363 by hydraulic pressure for which reason it has swiveled thereto as at 366 one end of a piston rod 361. The piston rod 361 carries at its inner end a piston 368 enclosed within a xed cylinder 369. The cylinder is attached to an upstanding arm 310 integral with or secured to one end of the fixed slide 363. The cylinder is provided on opposite ends with ports 31| and 312 whereby the hydraulic medium is alternately introduced into the cylinder.

By reference to Figure 15, it will be noted that the cylinder 369 has terminating respectively at itsl ports 31| and 312 one terminus of conduits 313 and 314 which terminate at their other ends in a reversing valve indicated generally by the numeral 315. This valve is shown structurally in Figure 13 and comprises a valve bushingv316 secured in and carried by the plate or housing |85. Enclosed within'the bushing 316 is a spool type valve providing cannelures 311 and 318 alternately connecting the cylinder conduits 313 and 314 with the pressure conduit 319 extendand branch discharge conduits 380 and 38| connected with the branch conduits 3|1 and 2 |8. The valve has extending from ita stem 362 passing through a stuing box 383 carried by one end of the cylinder bushing. Surrounding the stem interiorly of the bushing isa coil spring 384 abutting on opposite ends with the stuiiing box spool portion of the valve. The outer end of the stem 382 is connected with a solenoid 385. The solenoid 385 has one end of its coil connected by the wire 336 with one terminal 381 of the double throw switch 332. The switch 332 is normally broken as respects the contact 381 385. is normally de-energized permitting the spring 384 to shift the truing valve in a direction it is shifted by the solenoid 385. The vother end of the solenoid 385 is electrically connected with the opposite lead to that to which the Aswitch arm of switch 332 is connected. The truing tool carriage 3 15 has rotatably mounted therein a shaft or screw 388 which carriesV at its inner end a diamond or other truing tool for operation on the face of the grinding wheel. 'This screw in practice is adapted tobe incrementally actuated in a direction toward the grinding wheel for which purposeit has secured to it, see Figure 5, a ratchet 389 adapted tocooperate with a pawl 398 pivotally attached to an arm 39| oscillatable about the axs ofthe screw shaft 388. The upper end of t e arm 39| is suitably connected to the movable core of a solenoid 392. .These parts are 'all enclosed within a suitable housing or guard 393 the truing mechanism and adapted yto be attached to the truing carriage 365. The diamond of the screw shaft 338 should at all times bear a definite relation to the operative surface of the grinding wheel 38 that it may be readily placed the movable core yof associated with- 383 and adjacent electrical conduit or so that the solenoid in operation. For this reason, the arm 39| is wheel.i Therefore, simultaneous with this compensation and through the solenoid 341 the diamond is adjusted with respect to the wheel thereby at al1 times maintaining a deflnite relation between the diamond and the wheel.

The solenoid.392 is electrically connected as by the wire or nelectric conductor 394 with the from a grinding machine, it is desirable that the conductor 386 connecting the contact 381 of switch 332 with the truing device valve solenoid 385. From this it will be seen that simultaneous with the shiftingA of the valve of the ltruing device the diamond is actuated in a feeding direction with respect to the wheelthereby removing a predetermined amount of material from the operative surface of said wheel. This.w ill again throw the work and grinding wheel surface out of operative relation and might result in the worknot reaching its size before'the roller |56 of the oscillatable carriage |31 reached the left hand ergize solenoids :B92 and 395 for not only feeding the diamond with respect to the grinding wheel, but also for compensating or adjusting the position of the grinding wheel as .respects the work in accordance with the amount of stock being removed from the operative face of the wheel.

In the automatic production of workpieces truing of the wheel take place at predetermined intervals i-n the cycle of operation of the machine. For example', after a predetermined number of work pieces have been produced by the machine, To accomplish this result, the slide |28 has mounted thereon a housing or casing 391 enclosing a counting mechanism and the switch 332 which is automatically actuated. The details of this mechanism are shown in Figures 10, 1l and 12 and comprise a vertically shiftable plunger 398 having rotatably secured in its upper end a roller 39.9. This roller 399 is adapted to be engaged by cam face 400' on the adjustabledog |98 carried by the plate member |53. The

plunger 398 is connected with a lpivotally mounted arm 40| and oscillated'ina clockwise direction by a spring pressed plunger 402 for maintaining' the roller 399` in its -normal upward position.

'teeth of a ratchet 406 formed integral with a sleeve member 401 loosely journaled on the shaft 403. Pinned or otherwise secured to the ratchet 406 is a switch actuator plate 408 having the lug 409 projecting from its surface. The parts are so arranged that each movement of the plate |53 in a`given direction causes a depression of the plunger 398against the yielding resistance of spring plunger 402. This depression of the plunger 393 causes oscillation of the arm 404 which through the pawl 405 advances the ratchetl 406. The advancement of the ratchet 406 may be one or more teeth on the ratchet dependingupon the particular`setting ofthe parts, which in turn is determined by how many pieces it is desired to finish between each truing of the grind ing wheel. The cam lug 409 eventually reaches a position to engage switch plunger 4|0 for rearwardly shifting said plunger and effecting the closing of the switch 332.by engaging the contact 381'. It is to be understood that more than one switch cam lug, such as 409, may be provide ed on the plate 408 for thereby closing the switch more than once for each complete revolution of the said plate and its actuating ratchet. This is determined again by the particular number of pieces it is desired to finish between successive truing operations.

In order to prevent a truing of the wheel during the grinding operation, the switch 332 is electrically connected with the switch 330 as above described, so that this truing can only take placev when lthe parts are in a fully retracted position, which' is the only time that the switch 330 is closed. It is believed that without further explanation the complete operation of the improved automatic grinding machine will be thoroughly un derstood. Y

What is claimed is:

' rf1. In a grinding machine of the class described the combination of a bed, a grinding wheel carriage pivotally mounted on the bed, a work support carried by the bed, an hydraulically actuated reciprocating motor operatively associated with the carriage for effecting its oscillation toward and from'the work support, an hydraulic circuit for operating the motor, and means oper-l carriage pivotally mounted on the b ed for oscillation toward and from the work supporting mechanism, :hydraulically operated reciprocating means including a cam for effecting the oscillation of the carriage, an hydraulic circuit for, effecting and controlling the operation 'of the hy- Cdraulically actuated means, and means operable by vsaid hydraulically actuated means for controlling the rate of oscillation of the carriage.

3. In a grinding machine of the class described the combination of a bed, a work supporting mechanism carried by the bed, a grinding wheel carriage lpivotally mounted on the bed for oscillation toward and frbm the work supporting mechanism, hydraulically operated reciprocating means including a cam for effecting the oscillation of the carriage, an hydraulic circuit for effecting and controlling the'operati'on of the hydraulically actuated means,Y and means operable by said hydraulically actuated means for controlling the rate of oscillation of the carriage, said rate controlling means comprising a valve, yield- .ing means for shiftingsaidv valveA to an inoperative position, and positive means associated with the hydraulic reciprocating means for shifting -said valve against the yielding resistance of said yielding means.

4. In a grinding machine of the class described -lating means, electro-magnetic means for shifting the reversing valve when the work is to the desired size, and means associated with the oscillating means for reversely shifting said reverslng valve.

5. In a grinding machine of the class describedu the combination of a work supporting mechanism, a pivotally mounted tool carriage oscillatable toward' the work at rapid and variable .feed rates and oscillatable from the work at a rapid rate, a cam wedge axially shiftable for effecting said oscillation of the tool carriage toward 'and from vthe work, hydraulically actuated means for actuating said cam wedge, an hydraulic circuit for'controlling said hydraulically actuated means,

a speed control valve in the hydraulic circuit, and

means associated with the axially shiftable cam wedge for actuating said speed control valve.

6. In a grinding machine of the class described the combination of awork supporting mechanism, a pivotally mounted tool carriage oscillatable toward the work at rapid and variable feed rates and oscillatable from the work at a rapid rate, a

cam wedge axially shiftable for effecting saidoscillation of the tool carriage toward :and from the work, hydraulically actuated means for actuating said cam wedge, an hydraulic circuit for controlling said hydraulically actuated means., a speed control valve in the hydraulic circuit, means associated with the axially shiftable cam wedge for actuating said speed control valve, and means for by-passing the rate `control valve during the oscillation of the carriage -away from the work support.

7. In a grinding machine of the class described the combinatipn of a work supporting mechanism, a pivotally mounted tool carriage oscillatable toward the work at rapid vand variable feed rates and oscillatable y,from the work at a rapid rate, a cam wedge axially shiftable for effecting said oscillation of the tool carriage toward and from the work, hydraulically actuated means for actuating said cam wedge.. an hydraulic circuit for controlling said hydraulically actuated means, a shiftable speed control valve in the hydraulic circuit, means associated with the axially -shiftable cam Wedge for actuating said speed control valve, a reversing valve in said circuit for controlling the direction of operation of the hydraulically actuated means, and a-pilot valve for determining the position of the reversing' valve and consequently the direction of actuation of the hydraulically actuated feeding means.

`8. In a grinding machine for producing successive work pieces to a predetermined size and finish comprising a work supporting mechanism,

a grinding wheel carriage rotatably supporting a grinding wheel, means pivotally mounting said carriage for oscillation toward and from the work supporting mechanism, additional means for mounting said carriage for translation toward and from the work supporting mechanism, hydraulicallyactuated means for effecting the oscillation of said carriage, electro-mechanical means for effecting the translation of said carriage, andmeans carried by the hydraulically' actuated means for energizing the electro-mechanicall means at a definite point in its cycle of operation.

9. In a grinding machine for producing successive Work pieces to a predetermined size and finish comprising'a work supporting mechanism, a grinding Wheel carriage rotatably supporting a grinding wheel, means pivotally mountingsaid carriage for oscillation toward and from the work supporting mechanism, additional means for mounting said carriage for translation toward and from the Work supporting mechanism, hydraulically actuated means for eifecting the oscillation of said carriage, electro-mechanical means for effecting the translation of saidn carriage, means carried by the hydraulically actuated means for energizing the electro-mechanical means at a definite point in its cycle of operation, and means for controlling the `rate of actuation of the hydraulic means for thereby controlling the rate of oscillation ofthe tool carriage and the finish on the Work.

10. In a grinding machine for producing successive work pieces to a predetermined size and finish comprising a work supporting mechanism, a grinding wheel carriage rotatably supporting a grinding wheel, means pivotally mounting said carriage for oscillation toward and from the work supporting mechanism, additional means for mounting said carriage for translation toward :sov

the carriage toward the work and effecting a reverse oscillation thereof.

1l. In a grinding machine of the class described for producing successive work pieces tp the same size and finish` the combination of a. work supporting mechanism, a grinding wheel .carriage pivotally mounted adjacent the work supporting mechanism for oscillation toward and from the work supporting mechanism, hydraulically actuated means foreflecting the oscillation of the grinding wheel carriage, means operable by the said hydraulically actuated means for controlling the rate of oscillation of the carriage and consequently controlling'the finish on the work, and means engaging the work for. stopping further oscillation of the carriage toward the work supporting means when the work reaches a predetermined desired size 'and for effecting reverse oscillation of the carriage.

12. In a grinding machine.. of the class described for producing successive work pieces to the same size and finish the combination of a work supporting mechanism, va grinding wheel carriage pivotally mounted adjacent the work supporting mechanism for oscillation `toward and from the work supporting mechanism, hydraulically actuated means for effecting the oscillation of the grinding wheel carriage, means operable by the said hydrauliclly'actuated means for controlling the rate of oscillation of the carriage and consequently controlling the finish on the work, and means engaging the work for stopping further oscillation of the carriage toward 'the a predetermined desired size and for eiecting reverse oscillation of the carriage, said hydraulically actuated means including an hydraulic' circuit and a-reversing valve therein, electro-magnetic means for effecting the shifting of the reversing valve in one direction and mechanically controlled means for effecting the shifting of the said valve in the opposite direction, and means interconnecting the electro-magnetic means and the means operable by the work forsaid motor, a reversing valve in said circuit; a

pilot valve for controlling the position of the reversing valve, means energizable upon reducing the work to the desired size for shifting said pilot valve in one direction, and mechanical means associated with the wedge cam for shifting said valve in the opposite direction.

14. A feeding mechanism for grinding machines in which the work 'is rotatably supported comprising a grinding wheel, a pivotally mounted carriage for said grinding wheel, an laxially shiftable wedge type cam for effecting the oscillation of said carriage, an hydraulic motor for shifting said cam, an hydraulic circuit for actuating said motor, a reversing valve in said circuit, a pilot valve for controlling the position of the reversing valve, means energizable upon reducing the work to the desired size for shifting said pilot valve in one direction, mechanical means associated with the wedge cam for shifting said valve in the opposite direction, and means in said hydraulic circuit operable upon movement of the Wedge cam for controlling said circuit and consequently the rate of movement of the wedge cam and rate of oscillation of the grinding wheel carriage.

15. A feeding mechanism forV grinding machines in which the work is rotatably supported comprising a grinding wheel, a pivotally mounted carriage for said grinding wheel, an `axially shift# able wedge type cam for effecting lthe oscillation of said carriage, an hydraulic motor for shifting said cam, an hydraulic circuit for actuatingsaid motor, 'a reversing valve in said circuit, a pilot valve for controlling the position of thereversing valve, means energizable upon reducing the work to the desired sizefor shifting said pilot valve in one direction, mechanical means associated with the wedge cam for shifting said valve in the opposite direction, means in said hydraulic circuit operable upon movement of the wedge cam fr controlling said circuit and consequently the rate of movement of the wedge cam and rate of -riage in a retracting direction.

oscillation ofthe grinding wheel carriage, and

means associated with said wedge'cam for stop ping further movement thereof and consequently further oscillation of the grinding wheel car- 16..A feeding mechanism'ffor grinding machinesin which the work isrotatably supported comprising a grinding wheel, a pivotally mounted carriage for said grinding wheeljan axially shiftable wedge type cam for effecting the. oscillation of said carriage, an hydraulic motor for shifting said cam, an hydraulic circuit for actuating said motor, la reversing valve in said cirmeans associated with the wedge cam for shift' ing said valve in the opposite direction, means in said hydraulic circuit operable upon'movement of the wedge cam for controlling said circuit and consequently the rate of movement of the wedge cam and rate of oscillation of the grinding wheel carriage, means associatedwith said wedge cam for stopping further movement thereof and consequently further oscillation of the grinding wheel carriage in a retracting direction, and electro-magnetic means for rendering said stopping means inoperative for initiating a new feeding cycle.

17. In an automatic machine tool for automatically producing successive work pieces to the same size and with the same ilnish comprising a bed, a work supporting mechanism on said bed, a

of the tool carriage for controlling the nish on the work, and means for automatically stopping the said oscillation When the Work is reduced to the desired size. y

18. In an automatic machine tool for automatically producing successive work pieces tcl the same sizemand with the same finish comprising a bed, a work supporting mechanism on,

said bed, a tool carriage pivotally mounted on said bed, means for automatically presenting an unflnished work piece to said work Asupporting mechanism and automatically withdrawing a nished work piece therefrom, means for auto- 'matically actuating said work supporting mechanism to cause same' to terminally engage and support the work piece, means for automatically oscillating the tol carriage toward the work to eilect the desired stock' removal from the work, means for automatically controlling the rate of oscillation of the tool carriage for controlling the finish on the work, and means for automatically stopping the said oscillation when the work is reduced to the desired size, said automatic means including interlocked electro and hydraulic control means whereby they are sequentially actuated in timed relation.

19. In a grinding machine of the class de scribed ythe combination with a bed, a work support, and a. grinding wheel, of means for securing one of'said parts to the bed for oscillation toward and from the other, `an axiallyo shiftable cam for effecting the said oscillation thereof, an hydraulic motor for effecting the adjustment of the cam, an hydraulic system including a valve for controlling the operation of themotor, and automatic meanscontrolled by the size.

of the work for. automatically actuating the 1 valve.

20. In a grinding machine of the class dscribed for producing successive work pieces to a predetermined size the combination with.w a

bed, a work support, ,and a ngrinding wheel, of' means for mounting one of -said parts for oscil- 

